I. Field of the Invention
The present invention relates generally to a system used in construction of buildings and the like. More particularly, the present invention relates to a system used to join two substantially perpendicular members together squeaking and movement of an overlying member relative to the underlying supporting member.
II. Description of the Prior Art
It is very common to have two substantially perpendicular members joined in the construction of homes and other buildings. This type of assembly may, for example, be commonly found in floors, where one or more sheets of wood flooring, such as sheet plywood or particle board, are laid over a series of floor joists. Wood planking is still occasionally used. Whatever the composition, the wood or wood composite overlying the joists is known as the subfloor. Tile, sheet vinyl, carpeting, or finish flooring is then laid over the subfloor. The joists themselves are commonly supported by a foundation where such as block or poured cement. A beam, such as an I-beam, may be used to provide additional support for the joists.
Most commonly the overlying wood is simply nailed to the joists with flooring nails. However, over time, the wood subfloor becomes separated from the joists either through warpage or shrinkage and is raised somewhat above the joists. Two common problems result. First, the floors tend to squeak when walked upon in response to weight being placed upon the "spongy" subfloor. The squeak results when the wood surrounding the nail rubs against the shank of the nail in response to the weight. Second, the movement of the "spongy" subfloor causes grout between ceramic tile to crack and to become separated from the tiles.
The problem described is as old as subfloor and joist construction. Many approaches to resolving the problem of squeaking floors are known. The most direct approach to the problem is to refasten the subflooring to the underlying joists by nailing or screwing the floors back in place. However, this most direct approach is also the least practical in the event where a permanent subfloor-covering material such as tile or linoleum is in place. This method is also not very practical when a semi-permanent subfloor-covering material such as carpet is in place. It is simply not possible to renew the attachment of the subflooring to the joists without first removing or replacing the finish flooring.
The remainder of the known approaches attempt to resolve the problem from beneath the subfloor through entry from, for example, the basement or crawl space.
The apparently easiest composed of materials has been to insert a tapered wedge between the joist and subfloor. Typically, these wedges are made from a soft wood and are sold several to a pack. This approach does provide temporary relief from squeaking by filling the void between the top surface of the joist and the bottom surface of the subfloor. This approach, however, only attacks the symptoms but not the cause of floor squeaking, in that the wedge only serves to further separate the two pieces in the vicinity immediately adjacent the insertion point. Frequent maintenance of driving the wedge deeper may resolve the problem but, again, the solution is only temporary.
Another possible approach taken toward resolution of the squeaking problem is to refasten the subfloor to the joist by toe nailing the subfloor through the joist. However, this approach is not very effective for a variety of reasons. First, a nail does not function well if its head is not flush with the surface of the board through which it is nailed. Second, to be effective at all, the nail must fully penetrate the wood it is intended to fasten. This is not always easy to achieve where the work is being done blind with limited knowledge as to the thickness of the subfloor, and other features.
Third, the inserted nail may cleanly pass through the joist, but may result in the further separation of the subfloor from the joist if the point of the nail pushes against the subfloor without penetrating its surface or with only minimal penetration. The opposite problem is the fourth problem where a nail may be too long and may pass completely through the subfloor and exit through the finish flooring, resulting in obvious problems. Again, this is a very possible result where the repair is being done blind. This problem is compounded because joists are typically composed of soft woods, and the nail (or a screw) often countersinks itself. Again, the result is the pointed end of the nail exiting through the finish flooring material.
As an alternative to toe nailing, a wooden backer board is occasionally placed in the corner created at the juncture of the joists and the subfloor. The backer board is placed parallel to the joist. Once in position, the board is nailed to the joist. However, the board is not nailed to the underside of the subfloor, and the problem is little resolved because there is no direct attachment at the critical place.
A more elaborate method is known which involves the use of hardware, usually in the form of a strap-type bracket and one or more screws or bolts. The bracket is placed over the bottom side of the joist and the bracket pulls the joist against the underside of the subfloor by a nut and bolt fastener. This system is disclosed in U.S. Pat. No. 4,888,926, issued on Dec. 26, 1989, to Lutz and entitled "Floor Squeak Eliminator". This patent discloses a floor squeak eliminator that comprises a joist strap for fitting on the underside of the joist and a downwardly projecting threaded member secured to the underside of the subfloor. A nut engages the threads of the downwardly projecting member and draws the subfloor to the joist.
However, this system is characterized by a number of problems. First is the problem of the complexity of the system which requires nearly half-a-dozen parts and several steps for installation and adjustment. The second problem relates to the bracket which is a flat strap of metal. Upon turning down the nut, the metal may stretch or bend, thus requiring readjustment of the nut. The third problem is that the bracket must wrap around the base and both sides of the bottom end of the joist to be effective. This requirement is a problem if the joist is a part of a cold air return of a forced air home heating system. In such a system the duct of the cold air return is formed in part by a sheet of metal being placed over the bottom ends of two side-by-side joists.
Accordingly., the known systems of drawing together two substantially perpendicular members, particularly joists and subfloors, have failed to provide either effective or practical answers to the problem of squeak elimination.